Why not only 1??
Dear student,
In case of option (3) in this question, when a Hfr transfers its genome to the F- strain, sometimes the conjugation gets disrupted and the entire genome may not be transferred and only a part of the genome gets transferred. So the resulting genome gets a part of F- genome and remains F-. Hence both option (1) and (3) are correct.
Hence, option (4) is correct.
Regards.
In case of option (3) in this question, when a Hfr transfers its genome to the F- strain, sometimes the conjugation gets disrupted and the entire genome may not be transferred and only a part of the genome gets transferred. So the resulting genome gets a part of F- genome and remains F-. Hence both option (1) and (3) are correct.
Hence, option (4) is correct.
Regards.